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System Operation
The outdoor unit and indoor blower cycle on demand from
the room thermostat. When the thermostat blower switch is
in the
ON
position, the indoor blower operates continuously.
Two−Stage Compressor
The two stage scroll compressor operates much like the
standard scroll compressor with the exception the two step
compressor steps between low capacity and full capacity.
The steps occur when gas is bypassed through a vent port
in the first suction pocket. This bypassing of gas allows the
compressor to operate at low capacity if thermostat de-
mand allows, creating a more cost effective and efficient
compressor.
Full capacity is achieved by blocking the vent port with a
slider ring. The slider ring (vent port cover) is controlled by a
24VDC
internal solenoid in the open position allowing low
capacity. When energized the internal solenoid closes the
slider ring, blocking the vent port and bringing the compres-
sor to full capacity. Stepping can occur during a single ther-
mostat demand as the motor runs continuously while the
compressor steps from low to full capacity.
System Operation Monitor
The diagnostic indicator detects the most common fault
conditions in the air conditioning system. When an abnor-
mal condition is detected, the module communicates the
specific condition through its ALERT and TRIP lights. The
module is capable of detecting both mechanical and elec-
trical system problems. See figure 1 for the system opera-
tion monitor
IMPORTANT
This monitor does not provide safety protection. The
monitor is a monitoring device only and cannot con-
trol or shut down other devices
.
System Operation Monitor
Y
C
R
LED
LED’s
Figure 1
LED Functions
Alert LED (yellow) −
communicates an abnormal system
condition through a unique flash code. The alert LED will
flash a number of times consecutively, pause and then re-
peat the process. The number of consecutive flashes, de-
fined as the Flash Code, correlates to a particular abnormal
condition.
Trip LED (red) −
indicates there is a demand signal from the
thermostat but no current to the compressor is detected by
the module.
Flash code number corresponds to a number of LED
flashes, followed by a pause, and then repeated.
TRIP and ALERT LEDs flashing at the same time indicates
that the control circuit voltage is too low for operation.
Reset ALERT flash code by removing 24VAC power from
monitor. Last ALERT flash code will display for 1 minute af-
ter monitor is powered on.
